The present invention relates to medical systems and particularly patient monitoring systems for the acquisition, processing and display of data of critically ill patients.
When monitoring critically ill patients, it is often necessary to obtain a variety of medical data related to the condition of the patient. Various options are available for this purpose. The most frequently chosen options are the use of patient monitoring devices for the acquisition of physiological parameters, such as those of the electrocardiogram, of the blood pressure, of the oxygen saturation or of the respiration; the laboratory analysis of physiological samples, e.g. of blood or tissue samples, and, in patients treated by artificial respiration, the evaluation of settings and measurement values of the respiration device. Recently, particularly the data acquired by a patient surveillance monitor have rapidly increased in number, on the one hand because the technical progress achieved in the fields of sensor technology and microelectronics is beneficial for the monitoring of patients, and on the other hand because the increasing insight into the medical interrelationships has initiated a demand for the acquisition of further parameters.
Due to this recent development, the number of a patient's physiological parameters which can be acquired, processed and displayed in modern intensive care wards and operating theaters has become so large that even very sophisticated display instruments make it hardly possible anymore to quickly acquire the massive bulk of data and that a reasonable evaluation of these data by the medical staff is hardly feasible either. Since humans can only visually observe a relatively limited number of curves and varying measurement values simultaneously and draw correct conclusions from these observations, state-of-the-art patient monitoring systems clearly entail a so-called "mental overload" effect, i.e. an overstrain of the mental receptivity. This makes it necessary to develop methods for avoiding the above effect.
The existence of a clear interrelationship between the form of representation of physiological data and the medical staff's ability to interpret these data has been demonstrated in a study published in Anesthesiology, Vol. 83, pp. 1184-1193 and entitled "Visual Display Format Affects the Ability of Anesthesiologists to Detect Acute Physiologic Changes". This study evaluates different forms of presentation of physiological data and the speed and accuracy of the detection of changes in these physiological data as performed by the medical staff. This study comes to the conclusion that the physiological data can be interpreted in a distinctly faster and more accurate manner when presented in a graphical form. A similar result has been presented in a study published in Journal of Clinical Monitoring, Vol. 13, pp. 249-259 and entitled "An Integrated Graphic Data Display Improves Detection and Identification of Critical Events During Anesthesia" wherein a graphic representation of twenty anesthesia-related parameters is compared to a mode of representation performed by means of curves and numerical values of the type commonly used in patient monitoring devices according to the state of the art. As to the detection of relevant events by the medical staff, the conventional representation through curves and numerical values has proven to require several minutes, additional time in comparison to a new graphic representation.
Since, as described above, the number of parameters monitored in a critically ill patient is ever more increasing, whereas the size of the monitoring devices is hardly changing or is even reduced as a result of technical advances, the display of the totality of such parameters on the screen of a monitoring device will cause a dilemma. Frequently, certain monitored parameters are displayed not at all or only with insufficient size and quality on the screen of a monitoring device because the space. available on the monitoring screen is not sufficient for displaying all of the monitored parameters with satisfactory quality. Other parameters, although their monitoring would be beneficial from the medical viewpoint, are not monitored since the display space of the monitoring device is already exhausted by other parameters of higher medical importance.
Thus, it is an object of the present invention to provide a method and a device for the optical representation of medical data acquired by medical systems, wherein the data can be quickly acquired and evaluated by a viewer.